In recent years, various kinds of integrated-inverter electric compressors formed by integrally fitting inverter devices therein have been proposed as compressors for air conditioners mounted in vehicles. Generally, such integrated-inverter electric compressors for vehicle air conditioners are configured such that an inverter accommodating section (i.e., an inverter box) is provided on an outer periphery of a housing containing an electric motor and a compression mechanism, and an inverter device that converts direct-current power supplied from a high-voltage power source to three-phase alternating-current power and feeds the three-phase alternating-current power to the electric motor is fitted inside the inverter accommodating section, so that the rotation speed of the electric compressor can be varied according to the air-conditioning load.
Examples of integrated-inverter electric compressors having the above configuration are described in Patent Documents 1 and 2, in which the inverter device includes an inverter board including a power board having mounted thereon power semiconductor switching devices or the like that receive high voltage and a control board or the like having mounted thereon a control communication circuit, such as a CPU, that operates at low voltage; high-voltage components such as an inductor coil and a smoothing capacitor that minimize switching noise and reduce current ripple of the inverter; a power-supply terminal connected with a high-voltage cable; and a bus bar assembly for electrical wiring between these electrical components.
The electrical components constituting the aforementioned inverter device are accommodated within the inverter accommodating section (i.e., inverter box or outer shell) provided on the outer periphery of the housing of the electric compressor in view of vibration-proof and heat resisting properties so that the electrical components are made as compact as possible and can be electrically wired as readily as possible and also so that heat-generating components, such as the power semiconductor switching devices and the high-voltage components, can be properly cooled.
Patent Document 1: The Publication of Japanese Patent No. 3827158
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2006-233820